Sodium Dodecyl Sulphate – Polyacrylamide Gel Electrophoresis (SDS – PAGE) is a technique commonly used for the separation of proteins according to their molecular weight, based on their differential rates of migration through a sieving matrix (a gel) under the influence of an applied electrical field. SDS – PAGE was used in assessing the genetic diversity among twelve accessions of African oil bean (Pentaclethra macrophylla) germplasms obtained from NACGRAB (Ibadan) and five villages around Nsukka vicinity. Protein banding patterns were scored for presence and absence and analysed for genetic similarities and dissimilarities among the accessions. A total of 11 different bands were found in the accessions from NACGRAB and total of 9 bands were found in accessions from Nsukka zone. The highest number of bands (10) were found in Accessions A1 and A2 (Nac1 and Nac2) while the lowest (5) band was found in Accession A7 (Nac7). The banding pattern revealed that some of the bands present in the accessions from NACGRAB were absent in the accessions from Nsukka zone. A dendrogram constructed on the basis of genetic distance matrix by the Unweighted Pair Group Method with Arithmetic Mean Algorithm (UPGMA), using the NTSYS-pc software resolved the germplasm into three distinct clusters and six groups. Cluster one and two had six and five members respectively while cluster three had only one member. Cluster 1 was made up of three groups (1, 2 and 3), cluster 2 was made up of two groups (4 and 5) while cluster 3 was made up of only one group (group 6).